Lull 6K Service Manual - Manual (Page 183)

Supply, Pressure, and Return Hydraulics
Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K 5-39
(Ref. Fig. 5-26) The following procedures completes the steps necessary
for removal of the hydraulic pump.
1. Tag and slowly loosen two (2) hydraulic hoses (Item 1) and bleed any
remaining oil. Disconnect hoses from elbows (Item 2). Cap fittings and
hoses.
2. Remove four (4) capscrews (Item 11) and lockwashers (Item 10)
securing the two (2) flange halves (Item 9) to the hydraulic suction
hose (Item 12). Remove the flange halves.
CAUTION: Before removing support bracket or loosening capscrews that
secure the hydraulic pump to the transmission (Item 7),
support the pump to ensure that it does not twist or fall.
3. Remove two (2) capscrews (Item 19), lockwashers (Item 20), and
flatwashers (Item 21) securing upper pump support bracket (Item 22)
to the pump.
4. Remove two (2) capscrews (Item 3) and lockwashers (Item 4) securing
the hydraulic pump to the transmission.
5. Pull the pump straight out from the transmission and take it to an
appropriate area for further inspection.
CAUTION: To avoid contamination of system, cap hoses and cover
opening in transmission after pump is removed.
Inspection and Maintenance, Hydraulic Pump
The following steps describe cleaning and replacement of fittings and
O-rings for the hydraulic pump after it has been removed.
Models with Control Manifold Hydraulics (Ref. Fig. 5-24):
1. Remove and discard O-rings (Items 10 and 16).
2. Remove four (4) fittings (Items 9 and 14). Clean with appropriate
solvent and dry with compressed air. Inspect and replace if damaged.
3. Clean exposed areas of hydraulic pump with appropriate solvent and
dry with compressed air.
4. Lubricate and install new O-rings on pump.
5. Lubricate threaded portion of each fitting, including the O-ring. Install
two (2) connectors (Item 9) and torque to 205–235 in-lbs. Install two (2)
elbows (Item 14) and torque to 75–85 ft-lbs.
Models with Mid-Inlet Hydraulics:
1. (Ref. Fig. 5-26) Remove and discard O-rings (Items 6 and 8).
2. (Ref. Fig. 5-25) Remove pressure switch (Item 9).
3. Make notes of positions of hydraulic fittings shown in Fig. 5-25 and
Fig. 5-26. Tag and remove all fittings. Clean with appropriate solvent
and dry with compressed air. Inspect and replace if damaged.